The human sinovial and bi-condile temporo mandibular joint (TMJ), is a set of structures that permit an anatomical and functional relationship between both temporary bone and jaw. This joint allows all the mandibular movements and functions of the stomatognatic system. One of the main elements of the TMJ is the articular disc, that divides the joint in two compartments and also relates the condile bone to the mandibular fossa, an the articular eminence of the temporary bone. In order to obtain morphometric data, 10 adults discs from 60 years average and 10 fetuses discs from more than 28 weeks of gestation, were analyzed and measured. The articular dik from TMJ in adults agrees with those from literature and the fetus articular disk present a retrodiscal zone under developed. The anteroposterior diameter of the fetuses discs gave an average measurement of 6,77mm and their transversal diameter was of 9,23mm. The sagital plane measurements determined an anterior zone thickness of 1mm, followed by a medial zone of 0,59 mm. and a posterior zone thickness of 1,72 mm. On the other side, an average of 14,46 mm were obtained on the antero-posterior adult dics diameter. The transversal or cross-sectional diameter registred here a measurement of 20,08 mm. The sagital plane measurements determined the anterior zone thickness as 2,39 mm; the medial zone 1,60 mm and a posterior zone 3,29 mm. An important statistical significance was found in the correlationship between the anteroposterior and transversal or cross-section diameters in the fetus. In the adult instead, it was found a correlation between thicknesses of the anterior, medial and posterior zones. Therefore, temporo-mandibular disc joint variations are attributable to anatomical elements growth, such as masticatory function and the presence or absence of dental pieces. We believed this situation would be mirrored in the modeling of disc thickness at the posterior zone